From the prior art, some solutions are known for the production of such multifunctional sensors, containing ion-selective or enzymatic membranes. A recently developed technique uses photolithography ("photopattern") (see. S. Nakamoto, N. Ito, T. Kirigama, J. Kimura: Sensors and Actuators--13, 1988, 165; Y. Hazanato, M. Nakako, M. Maede, J. Shicno: Anal. Chimica Acta, 193, 1987, 87).